*COMDECK COMSEL 
SEL       SPACE  4,10 
**        SEL - SELECT PATH.
* 
*         RELEASE FIELD ACCESS. 
*         IF CHANNEL RESERVED THEN FAKE I/O STATUS AND RETURN.
*         RESERVE CHANNEL.
*         SELECT PATH.
*         VALIDATE ACK RESPONSE.
*         RETURN. 
* 
*         ENTRY  NONE.
* 
*         EXIT   (A) = 0, NORMAL RETURN.
*                    .LT. 0, HARDWARE ERROR OR NOT ACK STATE. 
  
  
 SEL      ENM    X                 ENTRY/EXIT 
          IF     -DEF,NOS,1 
          RJM    R.TAFL            RELEASE FIELD ACCESS 
          LDD    CHNRES 
          SBN    1
          ZJN    SEL4              IF CHANNEL ALREADY RESERVED
          RJM    RES               RESERVE CHANNEL
 SEL1     LDD    D.REQ2+C.PATH
          LMC    FCSP              SELECT PATH
          RJM    FFN
          ZJN    SELX              IF ACK RESPONSE
          MJN    SEL2              IF HARDWARE ERROR
          LMN    RCAB&RCAK
          ZJN    SEL3              IF PATH ABORTED
          LMN    RCNK&RCAB
          ZJN    SEL3 
          LMN    RCFL&RCNK
          ZJN    SELX              IF FLUSH IN PROGRESS 
          LCN    NADERRG           ABNORMAL PATH STATUS 
 SEL2     RJM    ERR               REPORT ERROR 
          MJN    SELX              IF FIRM HARDWARE ERROR 
          UJN    SEL1              RETRY
  
 SEL3     LDN    EVTABT 
          STD    EVENT
          LCN    0                 INDICATE NOT ACK STATE 
          UJN    SELX 
  
 SEL4     LDK    M.CSTOA+M.CSTIA   FAKE INPUT AVAIL + OUTPUT BELOW THRES
          STD    STATUS 
          LDN    0                 INDICATE NORMAL RETURN 
          LJM    SELX 
